I’ve long been a fan of the FlySky multiple channel 2.4ghz stick radios. Whether you need only two channels for a standard RC car setup, or want extra channels for 3-spead gearboxes, winches, and light controls and so on, they have a lot of the capabilities of premium branded radio gear, at a fraction of the price.
This does come at the cost of a clunky user interface - especially on the earlier FS-CT6B transmitter, which needs to be connected to a PC for even the most basic adjustments – but things have improved with each new model.
The FS-i6S first appeared around 2016, with a revised version in 2020, and are still for sale as a current model. They are also becoming available second-hand.
Cost, and Buying
You should expect to pay around 60 GBP to 80 GBP for a new transmitter and 6- or 10-channel receiver combo (RX part numbers FS-1A6B and FS-1A10B respectively).
Combos with different receivers are available, often at a more attractive price, but you need to be cautious - the 8-channel FS-A8S RX for example needs an entirely separate “Flight Controller” module to operate. It also to be said that these are sold as flight gear and will need some modification for ground vehicle use.
The market for used FS-i6S combos is not extensive, but they can regularly be found on a certain ubiquitous auction site. Used prices are around 40 GBP to 50 GBP with the 6- or 10-ch receivers, depending on exact specification and condition.
My first used FS-i6S combo came unboxed, with a white transmitter, the optional “Device Holder”, an FS-iA10B Receiver, bind plug, and an FS-CVT01 voltage telemetry sensor. It also had signs of corrosion from leaking batteries.
The second one was sold as unused and came boxed, with a black TX with the throttle return spring mod already done, another 10 channel FS-iA10B receiver, USB lead and quick start guide.
The contents will change according to the exact combination you bought, but all models come in a satin white card outer box with minimal but full colour printing. Inside, everything is protected by a layered foam inner box with a smaller inset lid.
A “quick start” guide and bind plug appear to be supplied as standard with both the 6 and 10 channel combos, optional parts not included in all are a USB cable, and a bag of “DIY parts” for the gimbals - which may or may not include a throttle return spring kit.
A manual does not appear to be included with any combo, but a PDF of the 2020 version can be found on the manufacturer’s website, and one for the earlier 2016 version was also easy to find online.
This immediately looks and feels to be a step up from previous FlySky units, with rubberised side sections, aluminium carry handle, and a less gaudy design. I would have liked to see some sort of visible external branding – and antenna – though.
Both sticks move in both directions, with the throttle (up/down) on one side (depending on “mode”) being on a soft ratchet. A kit of parts to convert it to sprung operation is included in some combinations, but otherwise you will need to buy a set. I just couldn’t find a UK, or even mainland European supplier so had to buy from China with a 3-week delivery time.
On other transmitters I’ve suggested swapping the parts from one of the directions you don’t need and making an external gate for that stick, but in this case I think things are too fiddly for that (see “Throttle Return Spring Modification”, below).
I found the throw on the sticks to be too long for my short thumbs, and immediately uncomfortable. Adjusting the sticks to their shortest length helped a lot.
Four switches are arrayed across the top front of the TX – two are 2-position, the other two are 3-position. A rotary, 3-position momentary switch (referred to simply as “knobs” in the manual) can be found on each of the top left and right shoulders.
Two momentary buttons are located on the back of the transmitter, approximately where the second finger of each hand fall when holding the unit normally.
Two power buttons flank the display – and you need to press (and hold down) both to turn the unit on or off.
The screen itself is quite small at 3 inches diagonally, but it’s touch sensitive. This immediately covers one of the few gripes I have about the earliest FlySky FS-CT6B transmitter (PC USB connection via a clunky and initially difficult to set up interface to make the most basic of changes such as servo trimming or reversing) and the previous FS-i6 model (display only screen, but at least you could make changes with the extra buttons.
As is the norm for most 2.4ghz transmitters, the FS-i6S holds four AA-size cells accessible though a panel on the rear.
The PS/2 trainer/comms socket of previous models is now on the underside and is joined by a Micro B USB socket.
The FS-i6S transmitter is available in black, or white with a grey front. Something it took me a while to notice is that the bottom of the TX isn’t flat, which makes it unstable when standing.
Throttle Return Spring Modification
The 2020 manual gives full instructions on how to modify the ratcheted throttle to a conventional (for surface vehicles) return spring. I found them to be accurate and useful, but did not need to disconnect any cable connectors, instead pulling the T-shaped antenna cradle out and to one side.
Having modified many flight transmitters, I have to say that this was fiddlier than average, and definitely the most invasive mod to perform.
the whopping 13 sets of servo/power/sensor bus pins on one end.
The case seems to be robust but won’t be in the least water resistant.
Power requirements – 4v to 6.5v DC – are stated on the outside. There’s also a tiny red LED, and hole labelled “UPDATE” that will accept the plastic pin on the bind plug. After the problems with attempting a firmware update on the TX (see later), I didn’t try to do the same with the RX.
Nb If you’re using Tamiya’s first in-kit ESC – the TEU101BK– be sure to use a UBEC unit to reduce the drive battery voltage down to a safe level.
The FS-1A6B receiver is almost identical in appearance and function, the major difference being fewer channels (only 6) and correspondingly fewer sets of pins.
The FS-A8S receiver is a tiny, one way (incapable of telemetry) unit with a single output and requires a separate flight controller module for use.
This optional extra is a plastic holder/bracket with aluminium sliding sections and fasteners designed to hold a mobile phone. Unlike the transmitter, it appears to be only available in white. My thought is that this could allow for improvements in single person action shots or video.
With the central clamp pad installed as supplied devices up to 120mm (plus a few more mm of foam squish) can be held, meaning almost any phone from the last few years is going to have to go in horizontally. However, with the sliding section opened fully, the retaining screws can be removed, and anything up to 174mm (plus that foam allowance) could be accommodated.
The holder fixes to the transmitter with a standard photography thread (1/4 inch, 20 tpi) with extra bracing through the lanyard fixing point. Any lanyard in use can instead be lashed through the loop provided on the bracket itself.
Pics: 010 bracket, 011 fitted
Voltage Telemetry Unit (FS-CVT01)
This is a small unit about the size of a UBEC or servo reverser. Two flying leads are attached, the first is a 3 pin, servo lead type that connects to the “i-Bus SENS[or]” pins on an FS-1A10B or FS-iA6B RX receiver.
The other lead terminates in two pins – a positive and negative – for the outer two contacts (usually red and black) on a Lipo balance lead. -100v to +100v can be measured – that’s a very high “S” multiple.
It would be possible to plumb these to other battery types if you make up the correct adaptor.
On an RC boat this would mean you could keep an eye on the drive battery, being sure you have enough charge left to get to shore.
On their own, these units retail for 8 to 10 GBP. One major caveat though – the screen on the TX does not integrate the sensor very well.
Nb speed and temperature sensors are also available.
The touch screen is a step up from previous models, but has a pixel count unlikely to impress anyone. The “touch” aspect of it is very effective, but there are still some boneheaded function placements in the command trees. The more I used it, the less I liked it – despite learning where things were and getting faster at it.
Overall, I think it’s an improvement over the buttons on the FS-i6 model (and a massive leap from the FS-CT6B before that), but have concerns about what this level of complexity means for a long lifespan.
I’ve had issues with a second-hand radio combo having such an odd setup that I had to copy the setup file from a “known good” TX to be able to use it – so I was pleased to see a “Factory Reset” option on the FS-i6S.
All settings – including model memory and receiver binding are lost when using this option.
Having plugged the binding plug in to the “B/VCC” slot on the receiver & stuck a 3-pin (or 2-pin) plug carrying 6v-ish DC into any of the other slots, the binding process is to turn on the TX, press the “Tools” button, then SYSTEM, then RX bind.
The process is almost instant, too fast to read the messages anyway. I think they were something like “Binding to RX … … Bind OK!”.
To set up any of the switches, press the “Tools” button, make sure you are on the FUNCTION menu, then select Aux. channels. The setup screen starts on Channel 5, with a message that you can’t use it as it “is used for FLY MODE!”.
The right arrow carries you the next channel (6 to 10), and pressing on the icon for whatever option is currently selected (“0” is the factory default) allows you to select Nul[l] (nothing), VRx (the “knobs”) STx (sticks), KEY (the buttons on the back of the TX) or SWx (switches).
A selection other than Nul[l] results in a second icon being shown, selecting that allows you to select what exact control of the class selected with operate that channel – SwA, SwB, SwC or SwD for the SWx (switches) option, for example.
Given that there’s a “6” in the model number of the transmitter, I was pleasantly surprised to find that you can assign channels 8, 9 and 10 to any of the “knobs”, switches, or “keys” – and they work on the 10 channel FS-1A10B receiver. Channel 5 may not be available, but a whole 9 independent channels is impressive.
Voltage Telemetry Setup
On the middle (home) page on the transmitter display, pressing the screen on the voltage readouts will move you on to a settings page. Swiping down’ you’ll see a check box for “EXT. RX”.
With an X shown in that box, the “RX” voltage shown on the home page will be that measured internally by the receiver. With a check mark (tick) shown, it will be the voltage measured by the optional external FS-CVT01 sensor.
The settings below it allow you to set the voltages at which point the transmitter will beep an alarm at you, but the interface is unfriendly, you’re clearly meant to set up for one sort of drive battery, and not swap between that and the internal receiver voltage.
If you’re running separate batteries for radio gear and for the drive, you won’t be able to see them at the same time on the home page, and on the voltage page, the display is very chunky and scrolling down far enough to see the external sensor voltage means you can no longer see the transmitter battery voltage line.
Versions, and Firmware Update
I was a little surprised to see the firmware version of my TX was 2.00 with a date of 08-Jul-2016 (Tools button, SYSTEM, scroll down to About FS-i6S). Checking the FlySky download page for the TX (https://www.flysky-cn.com/i6s-xiazai) shows the current version as 220.127.116.11, with a date of 2020/5/20.
Following the method in the manual (start the updater .exe, turn on TX, insert USB lead, Tools button, SYSTEM, Firmware update, Continue), I just couldn’t get the software to show ready to update, or to perform the update, despite some encouraging messages relating to “BG-i6S firmware update” and “FS-i6S simulator” setup and being ready to use.
Rebooting the PC, using a different USB lead, trying things in a different order, watching Youtube videos on “successful” updates (where the version number and date on the TX didn’t change, BTW), nothing worked. Each time the only way to exit the firmware update on the TX was to remove one of the batteries.
Trying to read up on possible solutions showed it was very possible to “brick” the transmitter during a failed firmware update, rendering it useless. I decided to stop trying – better an out-of-date TX than a completely dead one. I wouldn’t worry about it on models without the facility, which is probably 99% of the transmitters I’ve ever used.
Although only virtual, I think it’s worth mentioning. For a start the layout is much clearer than I’ve come to expect and eschews multiple languages and useless technical information in favour of useful information such as how to fit a throttle return spring, modify those “knobs”, and so on. The translation, grammar and spelling are all better than average too.
I can’t really recommend an FS-i6S combo for someone who just wants a simple, off the shelf 2-channel set, but if you need/want all those extra channels, switches and so on – and don’t mind doing a bit of modification and have the time and patience to set it up, I can’t think of anything that comes close to it for a remotely similar price.
I’ll certainly be looking out for a couple more bargain priced sets (new or used) to add to the stockpile.
Greater complexity does mean more bullet points to consider:
|Plus Points||Neutral Points||Minus points|
| • Looks and feels to be higher quality than previous FlySky offerings
• 4 battery power
• USB and PS/2 connectivity
• “6 channel” TX actually gives you 9 channels on the 10-channel RX, which will surely cover most if not all of what you are likely to want to do with a wheeled RC vehicle.
• Provision for phone mount. Even more of a plus if the cradle itself is included in your package.
• Common 6-channel and 10 channel RX are drive battery voltage telemetry capable. Again, even better if one is included.
• Not being able to turn off the TX without first turning off the receiver is a clever touch.
• 5 model memory (not tested).
| • The touch screen is a step up, but is very low res. The “touch” aspect of it is very effective, but there are still some functions in boneheaded places.
• Somewhat lacking in identity, and not having a visible antenna on the TX, or even a notional stub just feels a bit weird.
• Dual dipole receiver antennas mark this combo out as being intended for aero use and could e slightly problematic to locate in an offroad buggy
• Cost is higher than earlier models – justified over the FS-CT6B, but a bit less so over the FS-i6.
• More complex, so more to go wrong.
• Complexity of choice in buying options, some of which may not do what you need them to.
While there are many nice features that weren’t there or previous models, they are somewhat offset by the higher price of a new FS-i6S combo.
The firmware update function not working didn’t affect my overall scoring as TX was still perfectly functional without it.
The main issue though is that aero style throttle – buying extra parts and modifying the insides of the TX is something you just don’t have to do for the sort of 2 or 3 channel stick or steerwheel setups that are sold alongside the average RC car or as part of a “deal”. If that’s what you’re looking for then this set really only scores a 3, maybe 4 out of 6.
Another big issue for me is the basic nature of the screen, and how poorly the optional battery voltage telemetry sensor is integrated.
If you want/need up to 10 channels to control your RC model, then, complexity is unlikely to be a problem for you, and I’d give the FS-i6S combo 5 out of 6 for the great value. However, a complex model is also likely to be expensive – and a multichannel set from a premium manufacturer may not be such a high proportion of the overall cost.
(See our notes on rolling the dice.)
Written by TB member Jonny Retro